When All Light Goes Out
by Gryph
Summary: Mild Slash: Dean/Castiel. Alternate ending to 5.21 Two Minutes To Midnight, where Dean is infected with the Croatoan virus. WARNING: Major Character Death. Written for the 2013 SPN Reversebang Challenge.


The thing that Dean remembered most clearly was that he never saw the Croat coming.

The mission seemed simple enough, go to Niveus Pharmaceuticals and blow the place sky high, destroying the entire store of Croatoan virus that Lucifer planned to unleash on the world. Dean had seen what the world would look like in a few years if that virus got loose, when Zachariah had sent him forward in time to 2014.

It hadn't been pretty. If events continued as they did, humanity would be reduced to a handful of survivors, including a band of resistance fighters led by his future self. And Sam—Sam was a monster, Lucifer wearing his skin like it was an Armani suit. Dean couldn't let that happen. Although Zachariah had told him the only way to prevent it was for him to agree to be Michael's vessel, he had a different plan to derail the whole apocalypse party.

Step number one—stop the Croatoan epidemic.

With a duffel bag full of explosives, Sam, Dean, Bobby and Cas had stormed Niveus. When they arrived, the trucks were already being loaded with pallets of the demonic virus, all neatly packaged in vials for distribution to hospitals and doctors' offices as a vaccine against swine flu. As they watched, one of the trucks closed up and began to pull out of the lot. Castiel split from them to go spike the driver and smash the gate control to prevent any other trucks from leaving. But that delay gave the demonic guards inside the loading dock enough warning to infect some of the factory workers before Bobby, Dean, and Sam could get there.

When they stepped inside the door, a crowd of Croats were waiting for them. They heard them before they saw them, as the growling, slavering group of men and women still wearing their hardhats and reflective vests, rounded a corner from behind a stack of pallets.

"Holy hell," Bobby breathed. Unlike the boys, he hadn't seen the effects of the Croatoan virus up close. What should have been the whites of their eyes were instead pools of blood, their irises standing out like bright points. The guttural growls that issued from their throats sounded like meat being shredded, wet and primal. Dean and Sam were already firing, each bullet tearing through skull and grey matter to erupt in a fountain of blood on the other side. Bobby's shotgun joined the cacophony. Bodies fell in all directions, frozen in the rictus of their pain.

Once quiet settled, they could hear the distant screams.

"There's still people here," Sam said. He looked at Dean, already edging in the direction of the screams.

"Sam, no," Bobby said.

Dean handed the demon knife over to Bobby. "Wait here."

Sam tucked the pistol into the back of his pants and raised a shotgun to his shoulder as he went looking for people to save. Dean shrugged at Bobby and followed Sam.

* * *

Dean was ushering the last woman out of the warehouse when a sharp yank on one leg pulled his feet out from under him. He jammed his shoulder when he hit the ground, but still managed to swing his pistol around and blow the top off the head of the Croat. But not before the son of a bitch sunk its teeth into his leg just above the ankle. Dean yelled as the pain hit.

Then a moment later, realization followed. Dean swallowed hard and let his head fall back to the cement floor.

He was infected.

Maybe not. Maybe the bite didn't break the skin. Maybe there had been no transfer of blood. Maybe—

Dean sat up, scrambled backward from the bloody corpse. The leg of his pants was shredded from mid-shin to ankle and dark with blood. His heart sank as he pulled the fabric aside to reveal two crescents shaped wounds, the hunk of flesh between them partially excised. Blood flowed freely from the bite, soaking the top of his sock.

_Fuck!_ He had thought all these Croats were put down, but that one must have just been wounded.

The others would be waiting for him, leaving themselves vulnerable, until he returned. He pulled the belt from his waste and looped it around his leg just under the knee, and cinched it tight. His vision grayed and he bit the inside of his cheek to keep from screaming. The vaccine seemed to work quickly, but when he and Sam had first encountered the virus being transmitted directly from person to person, the incubation period was substantially longer. If he could just slow it down, keep from turning before he got back to the others, maybe they could figure something out. Maybe they could—

Who was he kidding?

There was no cure for Croatoan. Even in 2014, they hadn't figured out a way to stop it. He would turn into a monster.

He should just eat his gun right here and now. This was not how he imagined himself ever going out, on the end of his own gun. Even when he'd spent that year of short time waiting for the crossroads demon to collect payment, he'd never seriously considered offing himself. He wanted to keep fighting until the bitter end, for Sam if not for himself. With a shaking hand, he brought the barrel of his pistol up under his chin. His eyes vision swam, and he closed his eyes as he tried to slowly tightened his finger on the trigger.

After a moment, he dropped the pistol back in his lap. He couldn't do it. He just couldn't.

"Dean!"

Castiel rounded the corner, holding the sawed-off shotgun in front of him in both hands, like he wasn't sure if should shoot it or use it as a club. His eyes went wide as his gaze flicking down to take in Dean's blood soaked pants leg.

"Cas! I need help!" Dean called, levering himself upright using his shotgun as a prop.

Cas rushed over to where Dean was struggling to stand and slipped one shoulder under Dean's arm, using one free hand to pull his arm across his shoulders.

"What—," Castiel began to ask.

Dean cut him off. "Later. Let's just get out of here."

Together, they limped back toward the loading dock. As they arrived, Bobby and Sam knelt next to a pallet of boxes, just finished setting up the explosives.

"Let's move!" Sam yelled, helping Bobby up and pushing him toward the door before taking Dean's other side. Between his brother and his friend, Dean was swept out of the building before he had a chance raise an objection or warning.

Bobby blasted another Croat-infected dockworker as they crossed the parking lot. Dean, Sam, and Castiel looked like contestants in a three-legged race as they hobbled as fast as they could toward the van. Bobby threw open the side panel; Dean dived into the open space. Castiel climbed in after him as Sam ran around the front to get in the passenger side.

Bobby's hand hesitated on the handle of the sliding door as he caught a good look at Dean's leg. His grip on the shotgun tightened, before he caught Dean's eye. An unspoken promise passed between them, a reassurance that Dean wouldn't do anything to endanger them, and an affirmation that Bobby would do what needed to be done if Dean asked him.

But Dean had already vowed that no matter what, he wouldn't allow the man he'd come to think of as a father to be responsible for putting down another person he loved.

* * *

Bobby eased the van off the asphalt onto a dirt road that disappeared into the trees. He slowed to a stop just out of sight of the dark ribbon. Before he even threw the gear lever into park, Sam bolted between the seats into the back and knelt next to his brother. He looked at the torn, bloody jeans and the leather belt cinched tight across Dean's thigh, then up into Castiel's face above where Dean leaned against the angel's chest.

"What are you waiting for, Cas? Heal him already!" Sam demanded. Dean's face was pale but he opened his eyes at his brother's voice. His hand trembled as he reached toward Sam.

Cas tilted his head, casting his eyes downward. His gruff voice dropped deeper. "I can't, Sam. As I told you before, I am cut off from Heaven."

Sam's eyes widened as his throat closed up. "Then he's—"

"Don't talk about me like I'm not here!" Dean growled.

Metal hinges squealed as Bobby pushed open the driver's door and bolted from the van. Sam watched as Bobby walked around to the front of the van, his hands clenched into fists as he cursed under his breath. The older man stopped with his back to them, then raised his face to the sky. With a sad shake of his head, he returned to the side of the van and yanked open the panel door.

Dean blinked at the light that flooded the back compartment, raising a hand to shield his eyes, already growing sensitive to the brightness. But he could see the pained look on Bobby's face, the same look he imagined the hunter wore when he'd had to kill his own wife after she was possessed by a demon.

Sam shook his head, a curt gesture of denial. "No, there has to be _something_ we can do! Call Michael, tell him Dean will say yes if he cures him. I thought they wouldn't let anything happen to Dean because Michael needs him! Can't we—"

"Michael has taken another vessel," Castiel said, his tone angry and his words clipped. "Dean is no longer any concern to Heaven. We cannot count on any of my brethren for help."

Sam opened his mouth like he was about to start again, but Dean pushed himself more upright. "It's over, Sammy."

"No!" Sam shook his head again, grabbing onto Dean's jacket with both hands. "No, I don't accept that!"

Bobby fisted a handful of Sam's sleeve and tugged him away from his brother. "Come 'ere, boy. We need to chat." He gave Dean a knowing nod, and gradually pulled Sam out of the van.

Sam cast a frantic, worried look back at his brother, than followed Bobby a few steps away.

"You have an idea, Bobby?" Sam asked hopefully.

Bobby wrapped a hand around the back of Sam's neck. He looked Sam square in the eye. "You remember a couple of months ago, when Karen—," he began, but his voice broke. He cleared his throat. "There's no magic potion here, Sam. There's no lore, no spell, no deal that we can make to save your brother." Moisture gathered in the corners of his eyes. "Believe me, if there was, I'd be the first one all over it like white on rice."

"No, Bobby—," Sam tried to pull away, but Bobby's grip was like a vice.

"Stop, son. Stop trying to change what can't be changed." He pulled Sam closer as the younger man's face began to crumble. "Some things can't be fixed, no matter how much we wish we could."

Sam buried his face in Bobby's shoulder as a sob escaped him. "I can't do this again, Bobby; I can't lose him again," his muffled voice was wrecked with grief.

"I know," Bobby hugged his surrogate son tighter. "I know. But you got a chance to say goodbye. Now, while he's still... while he's still _him. _Don't waste it." He let his own tears fall freely.

* * *

Sam shuffled back to the van slowly, having stayed behind while Bobby returned ahead of him to say his own last words to Dean. Cas leaned against the hood of the van. Sam frowned as a thought came to him, and he veered toward the angel.

"Cas." Sam murmured. The angel's face when he looked up was pinched, the pain radiating from him like a heat. Sam instantly sensed what was causing Castiel's ache. "Oh my god," he whispered. "You're going to be the one—," he couldn't finish the thought.

Castiel winced, and his voice cracked when he spoke. "Dean asked me to," his fingers curled into air quotes, "'do what needs to be done'." He moved his hands behind his back and clenched them together, but not before Sam saw them tremble.

"Will you?"

Icy blue eyes locked with Sam's. "Yes." The one word held both a promise and an apology. "But it needs to be done before he turns, or he will go to Purgatory instead of Heaven."

"Heaven? You sure about that?" The question held and urgency. After Dean's time in Hell, the bargain with the crossroads demon, after all the killing and the screwing and stealing, Sam was a little taken aback.

"Of course."

Sam turned to stare at the horizon, a new idea forming in his head. "Once he's in Heaven, can someone bring him back, like Joshua did for us?"

"I don't know, Sam. Heaven is in chaos as the Apocalypse grows closer. I don't... I don't know if there is anyone left powerful enough who would. The archangels are gathering for the coming battle. I don't know if Joshua still tends the garden or not. And my Father," he frowned, "my Father has abandoned us all."

"Send me with him," Sam blurted out.

"What?" Castiel snapped, bristling. Sam imagined he could almost see angelic wings unfurling in anger. But he was undaunted.

"Send me with Dean. I want you to... to do me, too. It's the only way I can get away from Lucifer, keep him from wearing me like a cheap suite to the prom when he fights Michael."

"No." The pronouncement was dull with finality.

"Look, Cas, he's my brother. He's the only family I have left, the only family I ever really cared about. I'd rather be up there with him than down here dealing with this clusterfuck alone."

"No."

Sam pursed his lips. "Why not?"

Shaking his head, Castiel looked exasperated. "First, going to Heaven will not prevent your part in the Apocalypse. _You _ are still a needed vessel. The archangels would intercede. Second, I will not just kill you out of hand. It could still be viewed as a suicide, and Heaven would be denied to you." His expression softened. "I'm sorry, Sam. I can't. I won't."

Sam closed his eyes, choked back another sob. "Just... just take care of my brother, Cas."

"I will," Castiel inclined his head. "The bond I formed with Dean still connects us. I will not let allow him to suffer."

After a quick squeeze of Castiel's arm, Sam walked around to the side of the van. Bobby knelt just within the door, his hand on the back of Dean's neck as he spoke soft, urgent words. He couldn't see Bobby's face, but a tear rolled down Dean's cheek as Bobby pulled him into a fierce clasp. "Idjit," he heard Bobby whisper, the insult full of love instead of derision. Bobby stood and scrubbed a hand across his face, glancing quickly at Sam before he turned and stomped away.

"Sammy?"

Sam forced his feet to move, to walk the last few feet to where his brother waited to say goodbye. He sat on the edge of the van floor, his hands clasped tightly in his lap.

"Dean, I can't—," he began.

Dean reached out and wrapped his hand around Sam's shoulder. "You're gonna be okay, Sammy." He lifted his chin defiantly. "You tell Lucifer and Michael to fuck off." Dean blanched as a thought came to him. "I don't care _what_ kind of deal they offer you, Sam. You _do not_ bargain with them, you hear me?" His grip on Sam tightened. "You derail this thing and then go find some nice happy life to settle into."

"Dean." Sam tried again, but his throat closed up.

"No looking back, little brother. Just kick ass and keep moving forward."

Sam simply nodded, unable to find any more words. He threw his arms around Dean, holding on tight for as long as Dean let him, trying to memorize the feel of him, the smell of him, willing this moment to last forever.

"I'll see you soon, okay?" Dean whispered. "But not too soon, you hear me?"

Sam couldn't speak, so he squeezed harder.

"And don't go becoming some sleazy lawyer type who ends up not makin' it into Heaven, or I will be _pissed_." Dean finally pushed gently on Sam's shoulders. His time was growing short. Sam stood, choking back a sob, and followed after Bobby.

* * *

"Cas, help me up, we are going for a walk."

Castiel pulled Dean's arm over his shoulder and levered him up off the van floor. He looped his other arm around Dean's waist and pulled him tight against his side. "Where are we going?"

A shudder passed through Dean, and he twisted his head to one side. "Just into the woods. Far enough that Sam and Bobby can't see us." He tried to keep the pain off his face as something in his chest writhed and coiled. He could feel the hunger starting to clench in his stomach, the need for human blood burning in the back of his throat like bile.

Aside from the crunch of the leaves underfoot, they walked in silence. Castiel looked back over his shoulder several times before he finally stopped. "We are out of sight of the van, Dean."

Dean was sucking air, one hand clenching at his leg where the leather belt still bit into the swollen flesh of his thigh. "Lean me up against that tree," he jerked his chin toward a thick trunk. His voice was strained, sounding like it came from a throat full of ground glass.

Castiel shuffled over and helped Dean lean against the support, although he kept a hand on Dean's shoulder when he doubled over with his arms wrapped around his midsection. He drew in a shaky breath and straightened up. Castiel watched him, his eyes tight with concern.

"Listen up, Cas." Dean stopped, struggling for words. How did he tell the angel that he'd come to think of his as family, that he would have taken a bullet for him, as much as he would for Sam or Bobby. They'd come a long way in the last two years, from their first meeting in that abandoned barn when he and Bobby had summoned the angel trying to discover the nature of the being who had rescued Dean from Hell. And in the last year, Castiel had turned his back on Heaven, given up his power, his family—everything—to help Dean derail the apocalypse that Castiel had been told for the entirety of his existence _must_ happen. The battle between good and evil, between Michael and Lucifer, _had_ to be fought, despite the devastating consequences to humanity. But Dean had taught Castiel that human beings, were more important than the angelic grudge match. Well, at least _one _human being in particular.

Dean swallowed hard and tried again. "I don't know what I would have done without you, Cas." He blinked when his vision swam, but the red film that tinted everything wouldn't dissipate. It was starting. The words started tumbling out in a rush, before he could get embarrassed. "You saved me, Cas. I don't just mean from Hell," he snorted, "although that was pretty friggin' awesome. But you gave me something to believe in again. Not God or heavenly destiny or any of that crap. But you showed me that maybe humans really are worth saving. And that's something I'd started to forget."

Another spasm wracked him, and he slumped to the ground as his legs buckled under him.

"Dean—," Castiel knelt down, but Dean pushed him away.

"I need to end this now, Cas. Your angel sword. I need you to... to kill me before I turn into a monster."

Castiel pushed himself to his feet and stumbled back a couple of steps. Now that the time had arrived, he found himself hesitating. This was _duty_, something that he had never questioned before he met the Winchesters. Now it seemed that he questioned everything. "Why—"

"It has to be you, Cas. After what Bobby had to do to Karen, I can't task him. And Sam... well, Sam's gonna have enough issues without throwing that steaming pile of guilt on top of it all." He shook his head. "I'm sorry, but it's gotta be you."

"I understand." Castiel flicked his wrist, and the gleaming angel blade appeared in his hand. "But I am having... difficulty. I understand the necessity of it, but there is this feeling," he raised a hand and clenched a fist over his solar plexis, "like something inside me has been hollowed out. I...," his voice broke, "I don't know that I can."

Dean felt a growl trying to claw out of the back of his throat. Not his usual gruff vocalization, but a guttural, animalistic noise, wet and primal. He didn't have much time. "We have to hurry, Cas. I don't have much longer. You _have_ to."

Castiel knelt down. "Of all the humans I have met, Dean, you are the only one who has make me again feel the wonder that I knew when the world was young, when all of my Father's creations paraded into existence. I had lost that, but your soul shines like a beacon, showing me that there is still light in the world worth saving."

Dean fought to push down the beast he could feel gibbering in the back of his head, to keep from lunging at the angel and tearing at the delicate flesh to get to the blood that he could smell just below the surface. He wanted to stay with Castiel, to acknowledge the angel's declaration. He had always imagined that he and Castiel would have more time, at least until the end of the apocalypse, but after losing Ellen and Jo, he had come to realize that time was never going to be on their side. He wished he hadn't been so reluctant to let his feelings for the angel show before this.

"Cas, I... I'm gonna miss you, too. But you have to do this," he gritted his teeth as another howl of desperate need bubbled up; it pushed past his lips as a hungry rumble. He fell forward in the dirt, and started crawling toward Castiel. He lifted eyes that were now blood red toward the angel. "Now, Cas!"

Castiel nodded and quickly rose, raising the sword above his head. "I'm sorry, Dean. Please forgive me."

The blade flashed in the dappled sunlight as it inscribed a graceful arc. Blood sprayed across his white shirt as he buried the sword in the back of Dean's skull.

When Dean stopped twitching and lay still, Castiel finally pried his hand off the blade. He stumbled backward and collapsed to his knees in the forest undergrowth. Then he raised his face to the sky and screamed his pain for all his brethren and his Father himself to hear.


End file.
